In the color quality control field, industry standard colorimeters are used to measure color for purposes of quality control and communication of color parameters. These colorimeter devices are well understood in the field and produce accurate color measurements. When these devices are produced on a significant scale, it becomes paramount that product-to-product color consistency across the manufactured units is maintained. Specifically, where color or spectrum measurement instruments are used as part of a product quality control procedure, each color or spectrum measurement device used must produce consistent results, not just in a measurement to measurement capacity, but across all measurement devices. For example, it is of vital importance that two different users be able to use two different spectrophotometers of the same make and model, from the same manufacturer, and receive nearly identical color measurements.
There are several well-known methods and techniques for determining if the colors measured by a color measurement device are accurate. However, these methods fail to provide a mechanism for ensuring that each measurement instrument performs similarly to all other measurement instruments having the same production characteristics.
Additionally, there exist in the art various methods used to correct the measurement results among different instruments. However, the traditional correction methods fail to improve the inter-instrument-agreement (IIA) in many cases. Often there is no single reason for the failure of inter-instrument agreement approaches, as the underlying causes are complex and cannot be resolved using traditional approaches.
Furthermore, some color measurement instruments are unable to provide spectrum information. Where such instruments are capable of outputting only color tristimulus values, (e.g. a colorimeter), the traditional and routine techniques for obtaining inter-instrument agreement are unsuitable.
Therefore, what is needed in the art are systems, methods and processes to evaluate and compensate for the difference between the measured outputs of different instruments of the same or similar make and model. Furthermore, what is needed in the art are systems, methods and approaches to allow correcting color tristimulus values that are output by a measurement device so as to insure uniform measurements across different batches of devices produced at different times and/or with different components.